Illumina lowered by more than half the price for mapping all of the genes in a single human for research purposes to $4,000, the San Diego genetic testing company said Monday.

The move represented the latest chapter in the march toward a $1,000 genome that started a decade ago when scientists spent $3 billion sequencing the first human.

The new price is for individuals who are part of a group of at least 50 people who are sequenced for research purposes using Illumina's HiSeq machines at the company's laboratory in Sorrento Valley or facilities operated by partners, the National Center for Genome Resources in Santa Fe, N.M., and the Genomic Medicine Institute in Seoul, South Korea.

Groups of 10 to 49 will be charged $5,000 for each sequence, Illumina said.

Previously, the company charged $10,000 for individual sequences that were part of research.

Illumina's prices for whole genome sequences related to medical care remain unchanged at $19,500 for individuals, $14,500 for each patient who is part of a group of five or more, and $9,500 for those suffering from serious illnesses in which DNA mapping could produce an effective treatment.

The lower prices for research sequencing resulted from recent improvements to the HiSeq machine that boosted the devices output, said Jay Flatley, Illumina's chief executive officer.

The higher volume of business expected from the lower prices also should help push down the cost the work, he said.

Under the previous pricing structure, Illumina and its partners received more than 1,000 sequence orders, the company said.

Most whole genome sequencing of humans continues to be tied to scientific research. In the medical field, genetic testing tends to involve lower-priced mapping of smaller segments of the genome.

However, genomics experts say medical sequencing eventually will outpace research work.

Most expect the tipping point will come when the cost of an individual sequence reaches $1,000, an amount that would be within the affordability range of health insurance providers and patients who must pay out of their own pockets.

Once that happens, millions of people will be sequenced on a routine basis, and the data from their DNA will be tapped by doctors throughout their lives to explain and treat their medical problems, Flatley said.

"We're probably three to five years away from that magic number," he said. "We think the consumer market will just blow open."